Recently, a micro-chemical analysis (μ-TAS), in which a chemical operation such as pretreatment, reaction, separation, and detection of the sample is performed on a microchip, has been rapidly developed. The micro-chemical analysis uses only a small amount of sample, thereby allowing a high-sensitive analysis with a small environmental load.
Although the chip used in the chemical analysis including μ-TAS and in a biochemical analysis is structured so as to perform a predetermined operation to the sample in a channel formed on a substrate and in a channel such as a reaction reservoir, the sample is easily leaked from and dried in the channel, therefore, loss of the sample and deterioration of analytical sensitivity are easily occurred.
In the Patent Document 1, it is disclosed the chip, in which a minute tube for capillary electrophoresis is formed by joining a seal member made of a plastic film on a surface of a plastic plate-like member on which a groove is formed. In this manner, when the chip is structured such that the channel thereof is covered except a portion of an opening and may not be opened, it is considered to be effective with regard to above-described drying and leakage.
However, when the channel provided on the chip is covered and may not be opened, it becomes difficult to directly operate a liquid and components in the channel. Therefore, choices of operation has tended to be limited. And, an operation for transferring the liquid and the components in the channel to other region on the chip has been required.
For example, in order to realize a mass spectrometry of the components included in the sample, it is required to expose separated components in vacuum or in the air, and to vaporize by irradiating the same with a laser beam or the like. However, when separation has been performed by using a covered chip for separating, it has been difficult to directly vaporize the separated components because of an impeditive covering. Therefore, when performing the mass spectrometry of the material existing in the channel of the chip, it has been required to take the material to be measured out of the chip by using a driving mechanism such as a pump (Non-Patent Document 1).
Also, if the channel provided on the chip was covered, it has been difficult to replace the sample in the channel with another sample, and to directly operate the components of the sample from outside.
In the Patent Document 2, the electrophoresis chip, in which the reservoir filled with the migration buffer is sealed with the detachable seal, is suggested. The chip of the Patent Document 2 is aimed to speed up the operation by omitting the time-consuming process, in which the reservoir and the channel for migration are filled with the migration buffer without a space therein when operating. That is to say, the chip, in which the migration buffer is filled in the reservoir and the channel for migration in advance, and the reservoir is further sealed by the seal, is provided. In this chip, a portion thereof not being bonded is provided on a film such that the portion may be manually stripped from the substrate. And, the film covering the reservoir when using the chip is stripped from the portion being not bonded to expose the reservoir, and the migration buffer filling the reservoir is directly removed by using a pipette to replace the same with the sample liquid which is desired to be migrated, thereby allowing the filling of the sample.
[Patent Document 1]
Japanese Laid-Open patent publication NO. 2003-4700
[Patent Document 2]
Japanese Laid-Open patent publication NO. 2000-314719
[Non-Patent Document 1]
Daria Peterson, and four others, “A New Approach for Fabricating a Zero Dead Volume Electrospray Tip for Non-Aqueous Microchip CE-MS”, Micro Total Analysis Systems 2002, 2002, Vol. 2, pp. 691-693
[Non-Patent Document 2]
M. Baba, and five others, “DNA size separation using artificially nanostructured matrix”, Applied Physics Letters, 2003, Vol. 83, p. 1468